C-BASS has agreed to buy $8 billion of subprime mortgage servicing from National City. National City acquired the portfolio when it merged with Provident Bank and announced at the time that it planned to sell off Provident’s PCFS Mortgage Resources unit. C-BASS, a special servicing business jointly owned by mortgage insurers MGIC and Radian, will also acquire the PCFS servicing platform and residual interests from $900 million of mortgage securitizations. …